A is for America

Vidal described his homeland as the United States of Amnesia. Throughout his life he railed against how he felt it had betrayed its founding principles. "The United States was founded by the brightest people in the country – and we haven't seen them since," he said once. "Congress no longer declares war or makes budgets. So that's the end of the constitution as a working machine." He also had little time for the office of president, at least when that office wasn't occupied by a Kennedy, saying: "Any American who is prepared to run for president should automatically by definition be disqualified from ever doing so."

He told the Times three years ago that the US is "rotting away at a funereal pace. We'll have a military dictatorship pretty soon, on the basis that nobody else can hold everything together." There was a gleefulness in Vidal's acerbic denunciations of the US: significantly, the New York Times's obituarist yesterday charged that he "presided with a certain relish over what he declared to be the end of American civilisation".

B is for Bush

It's no surprise then that he detested George W Bush. Indeed, Vidal claimed the terrorist attacks of 11 September 2001 occurred because the Bush administration was "incompetent" and Bush himself was "inactive and inopportune". Vanity Fair refused to publish an essay he wrote reflecting on the attacks. In another essay, published by the Independent, he compared the attacks to the Japanese raid on Pearl Harbour, arguing that both presidents Franklin D Roosevelt and Bush knew of them in advance and used the disasters to advance their agendas. "We should stop going around babbling about how we're the greatest democracy on earth, when we're not even a democracy. We are a sort of militarised republic."

C is for Capote

Not all Vidal's targets were political. He had a lengthy feud with fellow writer Truman Capote. Capote, perhaps, started it. He gave an interview saying that Vidal had been thrown out of the White House for drunkenness and quarrelling with Jackie Onassis's mother. Vidal took Capote to court for libel, where the two traded insults. Vidal suggested Capote had "raised lying into an art – a minor art". Capote retorted: "Of course, I'm always sad about Gore. Very sad that he has to breathe every day." After the pair settled out of court, their feud continued – even outliving Capote. After the death of his nemesis in 1984, Vidal insulted Capote one last time, saying his death had been "a good career move".

D is for democracy

Vidal was sceptical about democracy in general ("Apparently, a democracy is a place where numerous elections are held at great cost without issues and with interchangeable candidates") and its American incarnation in particular ("Every four years the naive half who vote are encouraged to believe that if we can elect a really nice man or woman president everything will be all right. But it won't be.")

E is for essays

Gore Vidal was a better essayist than he was a novelist. That is taken as read in litcrit circles these days, and it will take a prodigious revisionist to make a case for the overblown novels and reverse the orthodoxy. Martin Amis, who has little time for Vidal the novelist, recognised the glory of the witty, learned, aphoristic essays. "Essays are what he is good at," he said. "He is learned, funny and exceptionally clear-sighted. Even his blind spots are illuminating." Playwright David Hare said today that Vidal didn't have "a fictional bone in his body", but that he was a "genius essayist".

Vidal was too forthright and opinionated to be a great writer of fiction, where many viewpoints have to be represented. He knew where he stood, never wavered from his Jeffersonian commitment to individual freedom, and found the essay the ideal form in which to express his views. His 1993 collection, United States: Essays 1952-1992, is a huge and majestic compendium that charts not just Vidal's rumbustious life but the culture and politics of the country he could love and hate in the same sentence. He had always vowed not to write a memoir – he eventually relented, though too late to write a great one – and saw his essays as an alternative, a repository of his wit, wisdom and occasionally venom.

United States: Essays 1952-1992, which won the National Book Award for non-fiction in the US, runs to 1,300 pages and contains 114 essays on subjects as diverse as Oscar Wilde, the legalisation of drugs, life in Mongolia and the journalist HL Mencken – a lifelong hero and a rare exception to Vidal's dictum that "journalism has always been the preferred career of the ambitious but lazy second-rater". There are also several shorter collections, mainly of his later essays, and A View from the Diner's Club, published in 1991, is the ideal place for the newcomer to begin.

His long essay on the American writer Dawn Powell, first published in his beloved New York Review of Books, is scholarly, charming and entirely convincing in its advocacy of a largely forgotten novelist. His 1989 essay on his friend Orson Welles is laugh-out-loud funny. He could do any voice he chose. What is needed now is a definitive collection of the essays – not even the bumper United States: Essays 1952-1992 contained them all. Whatever happens to the novels, the essays should always be in print. He was America's Montaigne.

Stephen Moss

F is for Fellini

Vidal loved making cameo appearances in film and on television. He once appeared as a cartoon simulacrum of himself in The Simpsons along with writers Tom Wolfe, Michael Chabon, John Updike and others; and also played himself in Family Guy and a US senator in Tim Robbins' movie Bob Roberts. He also starred in Gattaca, the 1997 sci-fi film with Uma Thurman and Ethan Hawke. Vidal's final film appearance was as a chat show host in the 2009 film Shrink, about a psychologist who treats Hollywood stars.

But arguably his most significant cameo came in in 1972 when he appeared in his friend Federico Fellini's film Roma. Fellini wanted him in the film because Vidal had been living in Rome since the early 1960s and become well-known on the literary scene. The appearance is most memorable for the fact that, for once in his life, Vidal's eloquence was definitively upstaged. "I was in the middle of take five when all hell seemed to break loose behind us," Vidal recalled. "I looked around. And there were four of the most beautiful white horses drawing an empty cart. 'Freddie,' I said, 'what the hell is that?' 'I don't know, Gordino. It looks nice. Don't you think it looks nice?' ... He kept adding things to the scene, then he would take them away, and finally the horses were gone. I suddenly realised that it didn't matter what I said, that I could be saying any nonsensible thing in my supposed interview, and that it wouldn't matter because I was part of his composition."

G is for Gore

Who was he? "I'm exactly as I appear," he said once. "There is no warm, lovable person inside. Beneath my cold exterior, once you break the ice, you find cold water." His friend, novelist Italo Calvino, insisted that Vidal had no unconscious. Vidal satirised the monstrousness of his vanity, without wholly undermining it. "I am at heart a propagandist, a tremendous hater, a tiresome nag, complacently positive that there is no human problem which could not be solved if people would simply do as I advise," he told the Guardian in 2005.

H is for homosexuality

"There is no such thing as a homosexual or a heterosexual person," he argued. "There are only homo- or heterosexual acts. Most people are a mixture of impulses if not practices." He claimed in his memoir Palimpsest that by the age of 25 he had had more than 1,000 sexual encounters with men and women, tending towards what he called "same-sex sex".

Vidal on the terrace of his mountain-top retreat at Ravello, Italy. Photograph: Eamonn Mccabe

I is for Italy

He lived for many years in a mountain-top retreat in Ravello on the Amalfi coast until he became too infirm to cope with the hills. In 2003, he moved to the Hollywood Hills in Los Angeles.

J is for Jack Kerouac

Vidal claimed to have had a brief affair with the beat writer. In Palimpsest he recalled finding, "to my surprise", that Kerouac was circumcised. It was Capote, not Vidal, who came up with the most waspish dismissal of Kerouac's work: "That's not writing, that's typing."

K is for Kennedy

Vidal never tired of telling us of his famous friends. His two memoirs – Palimpsest and its sequel, Point To Point Navigation, published in 2006 – describe friendships with Eleanor Roosevelt, Princess Margaret and Leonard Bernstein. He was close to John Kennedy and was a relative of Jackie Kennedy. "It is always a delicate matter," he once wrote, "when a friend or acquaintance becomes president."

L is for love

"Love is not my bag," he insisted. That said, Vidal lived for 53 years with former advertising executive Howard Austen. The key to their relationship, he repeatedly told interviewers, was that they did not sleep together. Austen was buried at Rockcreek Cemetery in Washington in 2003. Vidal said he wants to be cremated and have his ashes placed next to his longtime companion. "We share a plot, and I'll be there," Vidal told an interviewer. "And I'll be looking forward to seeing him."

N is for novels

He wrote 25 novels. His third, The City and the Pillar, published in 1948, was a coming-out story about a handsome, athletic young man, and was, he later claimed, blacklisted by the critical and literary establishment. "I sold a million copies and it caused much distress at the New York Times," he said. That blacklisting made it so difficult for him to get reviewed that Vidal took the pseudonym Edgar Box for a series of thriller novels and later gave up novels altogether for a time in favour of writing for the stage, television and Hollywood.

In 1956 MGM hired him as a contract writer: among other projects he helped rewrite was the screenplay of Ben-Hur, though he was denied an official credit. He also wrote the screenplay for the film adaptation of his friend Tennessee Williams's play Suddenly, Last Summer.

In the 60s he returned to fiction, writing a series of bestsellers: Julian (1964), about the Roman emperor who wanted to restore paganism; Washington, DC (1967), the first of his fictional chronicles of American history; and Myra Breckinridge (1968). Critic Harold Bloom cites Myra Breckinridge as a canonical work in his book The Western Canon.

O is for Oklahoma

Vidal formed an unusual bond with Oklahoma City bomber Timothy McVeigh. The two exchanged letters after Vidal's 1998 article in Vanity Fair on "the shredding" of the Bill of Rights and their friendship inspired Edmund White's play Terre Haute. "He's very intelligent. He's not insane," Vidal said of McVeigh. In Perpetual War for Perpetual Peace: How We Got to Be So Hated, Vidal argues that both the Oklahoma bombings and 9/11 attacks were provoked by "our government's reckless assaults upon other societies".

P is for politics

Vidal ran for elected office twice: once for Congress in 1960, in upstate New York; once for the Senate in California in 1982. He lost both times, but in the 1960 race garnered more votes than any Democrat in the district for the previous 50 years.

The interview when William F Buckley called Vidal 'queer'. Photograph: Bettmann/Corbis

Q is for queer

The conservative columnist William F Buckley once called Vidal a "queer" on live television in the 1960s. The exchange went as follows. Buckley compared anti-Vietnam war demonstrators to Nazis. "As far as I'm concerned," Vidal retorted, "the only pro- or crypto-Nazi I can think of is yourself." "Now listen, you queer," Buckley replied. "Stop calling me a crypto-Nazi or I'll sock you in your goddamn face. I was in the infantry in the last war." "You were not," Vidal retorted. "I was." "You were not."

As far as Vidal was concerned, he won that one and any other of the many TV duels in which he tilted: "I mean I won the debates, there was no question of that," Vidal said in a CNN interview in 2007. "They took polls, it was ABC Television ... And because I'm a writer, people think that I'm this poor little fragile thing. I'm not poor and fragile ... And anybody who insults me is going to get it right back."

R is for religion

"The great unmentionable evil at the centre of our culture is monotheism. From a barbaric bronze age text known as the Old Testament, three anti-human religions have evolved – Judaism, Christianity, Islam. These are sky-god religions. They are, literally, patriarchal – God is the Omnipotent Father – hence the loathing of women for 2,000 years in those countries afflicted by the sky-god and his earthly male delegates. The sky-god is a jealous god, of course. He requires total obedience from everyone on earth, as he is in place not for just one tribe but for all creation. Those who would reject him must be converted or killed for their own good. Ultimately, totalitarianism is the only sort of politics that can truly serve the sky-god's purpose." "God," he said on another occasion, "is a blackmailer."

S is for success

"Every time a friend succeeds, I die a little." On another occasion, he said: "It is not enough to succeed. Others must fail."

T is for television

He maintained that television is not for watching but for appearing on. He followed his own dictum scrupulously, commenting: "I never miss a chance to have sex or appear on television.

U is for upbringing

Vidal was named Eugene Luther Gore Vidal after his father, Lieutenant Eugene Luther Vidal, but he "got rid" of his first two names at 14. Before his army career Vidal Sr was an athlete who won a silver medal in the Olympic Games in Antwerp in 1920. "We knew each other for 43 years, we agreed on nothing and we never quarreled," said his son. "Only men can do this. Women can't." When his mother, Nina Gore, remarried, Vidal shared a stepfather with Jacqueline Kennedy Onassis. He detested his mother ("drunks are not much to be around") but worshipped his grandfather. "He was blind, so from the age of 10, I was reading to him. From the congressional record, from American history, poetry," Vidal said. "He was very good, he was extraordinary, he was my education."

V is for Vidal

He was not related to Vidal Sassoon. And while he often joked that Al Gore was a distant cousin, they weren't related either.

W is for Watership Down

"Gore Vidal is being interviewed on Start the Week along with Richard (Watership Down) Adams. Adams is asked what he thought of Vidal's new novel about Lincoln. 'I thought it was meretricious.' 'Really?' says Gore. 'Well, meretricious and a happy new year.' That's the way to do it." (from Writing Home by Alan Bennett, entry for 25 September 1984)

X is for X-rated

Vidal received negative press for two X-rated feature films with which he was associated. Michael Sarne's Myra Breckinridge, based on Vidal's 1968 novel of the same name, was a box-office disaster, despite the appearance of Raquel Welch, and was swiftly ranked among the worst films of all time. Vidal later sued unsuccessfully to have his name removed as the screenwriter of Caligula (1979) after the film's producer and Penthouse publisher Bob Guccione added pornographic scenes.

Y is for yellow

In a Yellow Wood (1947), Vidal's second novel, written aged 22, was inspired by the first line of Robert Frost poem The Road Not Taken ("Two roads diverged in a yellow wood ..."). It concerns a man who returns from war to become a Wall Street broker, but remains haunted by memories of nights of love with his wartime Italian mistress. When the fiery Carla turns up unexpectedly from his past, Robert must choose between convention and the fraught path of love and freedom. Vidal dedicated the book to Anais Nin, who, for him, embodied Carla. But later he said it was so bad, he couldn't bear to reread it.

Z is for Zoroaster

The protagonist of Vidal's epic 1981 novel Creation is Cyrus Spitama, an Achaemenid Persian diplomat of the 5th century BC and grandson of Zoroaster who travels the known world comparing the political and religious beliefs of various nation states of the time. Over the course of his life, Cyrus meets many influential philosophical figures of his time, including his grandfather (and founder of Zoroastrianism), Socrates, the Buddha, Mahavira, Lao Tsu and Confucius.

It's a sprawling, ambitious and today widely unread volume in which the political and religious systems of the day are dramatically compared. It also makes one recall an episode of The Simpsons in which Lisa holds up a book entitled Tome by Gore Vidal. "These are my only friends," Lisa complains. "Grown-up nerds like Gore Vidal. And even he's kissed more boys than I ever will." "Girls, Lisa, girls," Lisa's strait-laced mother Marge corrects her.

• This article was amended on 2 August 2012 because the original said Al Gore was a distant cousin of Gore Vidal, and that Gore Vidal and Howard Austen "had never slept together". Gore Vidal himself wrote that they did have sex when they met but did not sleep together after they began sharing a home.